The gas fired plant with an installed electrical capacity of 390 MWel and an installed thermal capacity of 170 MWth will have a high degree of flexibility to cover the fluctuating power demand in Bosnia and Herzegovina. The technical plant concept of the Project bases on two gas turbines with electrical output of approx. 128 MWel, two heat recovery steam generators and one steam turbine with an estimated maximum electrical output of 135 MWel. The gas turbines will be operated on natural gas fuel.
The steam turbine will be equipped with steam extraction taps to provide the required amount of steam to cater for the thermal requirements (90 MWth) of the district heating system.
The gas turbines and the steam turbine will each power a dedicated generator which is connected to a step-up transformer that will increase the voltage level to 220 kV in order to connect to the available Zenica 2 substation on the 220 kV voltage level.
The plant’s district heating facilities will be connected to the existing municipality’s district piping. The district heating system in the city of Zenica exists since 1967. Currently, the manufacturer of thermal energy for the district heating is ArcelorMittal Zenica. The total length of the district heating and hot water network is about 120 km. For the city of Zenica it is planned to increase the capacity of the district heating system and the amount of customers connected to the system.
It is planned to operate the plant at an extended peak operation mode (16h/day, 5 days/week) during the summer period and at a base load operation mode (24h/day, 7 days/week) during the winter period in order to supply the district heating system with the required heat. This will be the base case scenario at approx. 5’900 annual full load operating hours. The proposed configuration with the two gas turbines could adapt quickly to varying load situations, as the gas turbines can change their load relatively fast within a wide range.